by Andy Schooler, at The O2
Grigor Dimitrov beat David Goffin in three enthralling sets to claim the biggest title of his career to date.
Dimitrov triumphed 7-5 4-6 6-3 to become the first debutant winner of the prestigious season-ending tournament since Alex Corretja in 1998 and pocket a career-high cheque of more than US$2.5million.
The two finalists may have been unexpected ones but they produced a match fitting of its status - the biggest outside the Grand Slam finals of the year.
In was closely contested throughout its two-and-a-half-hour duration with Dimitrov - tipped up on this site to win the title at 12/1 - getting over the line on his fifth match point.
"It has been a tremendous two weeks for me," Dimitrov said in his on-court interview. "It is such an honour for me to play here. These two weeks have been two of the best weeks of my life. Without a doubt."
Sadly, particularly for Goffin, a crowd interruption appeared to play a significant part in the outcome of the match.
Serving at 2-3 30-0, a call from the crowd in the middle of Goffin’s first service motion resulted in an error. A double fault was the end result and from there things unravelled, a backhand into the net eventually handing Dimitrov what was to prove the only break of the deciding set.
Dimitrov missed three match points from 0-40 in Goffin's next service game but finally clinched victory behind his own serve when Goffin netted with a backhand volley.
The Buglarian, who had again enjoyed the majority of the crowd support, embraced his foe at the net before celebrating emotionally with his team, including coach Dani Vallverdu, the man he credits with helping revive his career.
Dimitrov slipped to 40th in the world ranking during the summer of 2016 but after a year which saw him reach the Australian Open semi-finals, win his first Masters title in Cincinnati and now this, he ends 2017 as world number three, behind only a certain Rafael Nadal and Roger Federer.
Goffin had beaten both Nadal and Federer en route to the final but many had expected him to be swept aside by the in-form Dimitrov given their group-stage match earlier in the week had seen the Belgian win just two games.
But he was always at the races in this one, making the early running and breaking in Dimitov’s first two service games to lead 2-1.
Watched by former England footballer David Beckham, it had been a nervy start from both men but they soon settled and Dimitrov, producing some great defence on his forehand side and using his backhand slice to good effect, broke back in the eighth game.
Dimitrov’s ability to hit his forehand on the stretch got him out of a spot of bother as he held for 6-5 and then struck in the next game, Goffin saving four set points but netting on the fifth.
Neither man had been able to hold easily on serve, the second delivery coming under particular threat, but the start of the second set saw a series of comfortable holds.
Dimitrov broke the pattern when he forced break point in the sixth game but Goffin produced a superb backhand onto the edge of the sideline – one which was originally called out only for Hawk-eye to confirm it was a clean winner.
It was to prove a big moment as Dimitrov cracked in the following game, two double faults putting him in a hole before Goffin delivered another winner on break point.
He served the set out impressively and with a tour-leading 22-5 record in deciding sets this season, must have felt confident heading into the third.
Despite break chances for both men early in the decider, the pair could not be separated until that fateful sixth game, one that made all the difference.
Goffin refused to link the shouting incident to his defeat, saying only: "I was not focused on the crowd, I was focused on what I have to do. I was in my match, so that was the key tonight.
"There's nothing else to say. Just was great match, great atmosphere."
He will now head to Lille for next week's Davis Cup final to be played in front of an even bigger crowd, mainly supporters of the home nation.
"Next week it will be also something different, playing for my country against France, in France, in an amazing stadium, 27,000 (people). So it will be noisy. But we will see. (I will) try to rest a little bit and be ready for another tough weekend."